Niobium (Nb): electron configuration, atomic mass and facts
Niobium (Nb) is element 41 of the periodic table, a transition metal in period 5, group 5. Its electron configuration is [Kr] 4d4 5s1, with electrons arranged in shells 2, 8, 18, 12, 1, and its standard atomic weight is 92.906 u.
▶ Watch Niobium’s electrons orbit in the interactive periodic tableNiobium at a glance
| Symbol | Nb |
|---|---|
| Atomic number | 41 |
| Atomic mass | 92.906 u |
| Category | Transition metal |
| Group | 5 |
| Period | 5 |
| Block | d-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d4 5s1 |
| Noble-gas shorthand | [Kr] 4d4 5s1 |
| Electrons per shell | 2, 8, 18, 12, 1 |
| Electronegativity (Pauling) | 1.6 |
| State at 20 °C | solid |
Where is Niobium on the periodic table?
Niobium is in period 5, group 5, in the d-block. The period number matches its 5 electron shells, and the block names the subshell its last electrons fill. In the same group, Vanadium sits directly above it and Tantalum sits directly below it. Elements in the same column of the d-block often have similar chemistry.
How to work out the electron configuration of Niobium
Put 41 electrons into subshells in order of rising energy, filling each before starting the next: 1s² (2), 2s² (4), 2p⁶ (10), 3s² (12), 3p⁶ (18), 4s² (20), 3d¹⁰ (30), 4p⁶ (36), 5s² (38), 4d³ (41). Niobium is one of the exceptions to this filling order: experiments show its ground state is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d⁴ rather than 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d³, because the neighbouring subshells are so close in energy. In shorthand, [Kr] stands for the 36 electrons of krypton, giving [Kr] 4d⁴ 5s¹.
How electronegative is Niobium?
Niobium has a Pauling electronegativity of 1.6, ranking 51 of the 100 elements with a known value (fluorine is highest at 3.98). That is in the middle of the range.
Frequently asked questions
What is the electron configuration of Niobium?
The electron configuration of Niobium (Nb) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d4 5s1. In noble-gas shorthand it is written [Kr] 4d4 5s1.
How many electrons does Niobium have in each shell?
Niobium has 41 electrons arranged in shells as 2, 8, 18, 12, 1.
What is the atomic mass of Niobium?
The standard atomic weight of Niobium is 92.906 u, so one mole of Niobium atoms has a mass of about 92.906 g.
Is Niobium a metal?
Yes. Niobium is a transition metal.
Explore nearby elements
More transition metals: Yttrium, Zirconium, Molybdenum, Technetium, Ruthenium, Rhodium. See all elements on the periodic table.